Paper shredders are used to cut paper into strips or fine particles. According to the size and shape of the shreds produced by the paper shredders, paper shredders are generally classifies into two major types, i.e. strip-cut paper shredders and cross-cut paper shredders. In the strip-cut paper shredder, the cutting blades are disposed regularly on the rotary wheels and cut the along the longitudinal direction into long stripes. In the cross-cut paper shredder, each blade has several hook-shaped cutting edges. The blades are disposed in a spiral way on the rotary wheels. The paper is not only cut along the longitudinal direction into stripes, but also cut in the transverse direction into chips. In this context, the paper stripes or chips are also referred as paper shreds.
Generally, the paper shredder has a trash basket or bin for accommodating the paper shreds. Since the light-weighted paper shreds freely fall into the bin and are accumulated in a random manner, the bin is readily filled with the paper shreds. When the bin is full, the paper shreds in the bin may hinder the follow-up paper shreds from falling into the bin. In a case that the paper shreds in the bin are turned back into the gaps between the cutting blades, a paper jam event occurs and the normal operation of the paper shredder is usually obstructed. For solving the paper jam event, it is necessary to empty or clean the bin when the bin is full.
For realizing whether the bin is filled with the paper shreds, the conventional paper shredder has a sensing module for detecting the paper shreds. When the bin is full, an illuminator emits a warning light beam to notify the user of emptying the paper shreds that are within the bin.
FIG. 1 is a schematic perspective view illustrating a conventional paper shredder. As shown in FIG. 1, the conventional paper shredder 1 comprises a shredder body 10, a bin 11 and a sensing module. The sensing module is disposed on the shredder body 10 and comprises a light emitter 12 and a light receiver 13. The light emitter 12 and the light receiver 13 are disposed near two opposite inner surfaces of the shredder body 11. The light emitter 12 is for example a light emitting diode (LED). Normally, the light emitter 12 continuously emits a light beam to be received by the light receiver 13. When the bin 11 is full and the paper shreds overflow into the receptacle within the shredder body 10, the light beam is obstructed by the paper shreds. Since the light beam is obstructed by the paper shreds, no light beam is received by the light receiver 13. Meanwhile, the sensing module realizes that the bin 11 is full and thus an illuminator is turned on to emit a warning light beam to notify the user.
The use of the sensing module to realize whether the bin is full, however, still has some drawbacks. For example, the illuminator is often erroneously turned on to emit the warning light when dust or paper shreds are accumulated or adsorbed on the surface of the light emitter 12 or the light receiver 13 because the light beam emitted from the light emitter 12 is obstructed by the dust or paper shreds. The phenomenon of erroneously generating the warning light is not caused by the full bin. For the cross-cut paper shredders, the phenomenon of erroneously generating the warning light is frequently found. For preventing from erroneously generating the warning light, it is very troublesome for the user to frequently clean the surfaces of the light emitter 12 and the light receiver 13.
Therefore, there is a need of providing a paper shredder with a dust cleaner so as to obviate the drawbacks encountered from the prior art.